The modern workplace is increasingly reliant on the use of networks. A network is a group of computer systems and associated devices that are connected by communications facilities. A network enables the transfer of electronic information among computer systems. Typically, each of the computer systems has local applications which may be invoked at that computer system. The local applications may receive input from a user at that computer system. Also, a local application displays output at that computer system.
It is useful for a user to be able to share an application invoked at a host computer system with another user at a shadow computer system. For example, sharing an application which generates a word processing document may assist an editor who is working with a writer to publish a document. In particular, the editor may wish to edit the document at the host computer system, while the writer views the document at the shadow computer system. In this manner, the writer may also provide input to the shared application and modify the document based on the editor's comments. Immediately, the editor may review this revised document. In addition, sharing an application may be useful for diagnostic testing by a technical person upon receiving questions from a user. For example, if the user has found that an application is not working properly, then the user may desire to share the application with the technical person. Then, the technical person can attempt to solve the problem, receiving input from the user describing the problem as needed.
Some conventional computer systems allow a user at a host computer system to share an application with a user at a shadow computer system. These conventional computer systems typically display the output of the shared application within a shadow window that is contained within a top-level window. The top-level window is created and controlled by the program that coordinates the sharing of the application. Unfortunately, because the shadow window is not a top-level window, the shadow window may not be minimized or maximized under the control of the operating system.
In addition, these conventional systems typically do not negotiate control of the shared application. Instead, either user may input data to the shared application, and all data is passed in to the application in the order it is entered. Moreover, typically, a user who is sharing an application may either view the application or control it (i.e., provide input to it). Conventional systems do not enable a user who is sharing an application to use non-shared applications. It may be useful, however, for a user to be able to use a non-shared application and still be able to view a shared application.
Also, various computer systems within a network may have differing display resolutions. For example, some computer systems may have a display resolution of 1024 by 768 pixels and other computer systems may have a display resolution of 640 by 480. Thus, it would be useful when sharing an application to accommodate the different display resolutions.
Furthermore, since the user of a shared application at the shadow computer system actually views the output in real time, it is important that the speed of transmission of the output data from the host to the shadow computer systems be optimized.